1 /* Low level packing and unpacking of values for GDB, the GNU Debugger.
3 Copyright (C) 1986-2013 Free Software Foundation, Inc.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "arch-utils.h"
22 #include "gdb_string.h"
33 #include "gdb_assert.h"
39 #include "cli/cli-decode.h"
40 #include "exceptions.h"
41 #include "python/python.h"
43 #include "tracepoint.h"
45 #include "user-regs.h"
47 /* Prototypes for exported functions. */
49 void _initialize_values (void);
51 /* Definition of a user function. */
52 struct internal_function
54 /* The name of the function. It is a bit odd to have this in the
55 function itself -- the user might use a differently-named
56 convenience variable to hold the function. */
60 internal_function_fn handler
;
62 /* User data for the handler. */
66 /* Defines an [OFFSET, OFFSET + LENGTH) range. */
70 /* Lowest offset in the range. */
73 /* Length of the range. */
77 typedef struct range range_s
;
81 /* Returns true if the ranges defined by [offset1, offset1+len1) and
82 [offset2, offset2+len2) overlap. */
85 ranges_overlap (int offset1
, int len1
,
86 int offset2
, int len2
)
90 l
= max (offset1
, offset2
);
91 h
= min (offset1
+ len1
, offset2
+ len2
);
95 /* Returns true if the first argument is strictly less than the
96 second, useful for VEC_lower_bound. We keep ranges sorted by
97 offset and coalesce overlapping and contiguous ranges, so this just
98 compares the starting offset. */
101 range_lessthan (const range_s
*r1
, const range_s
*r2
)
103 return r1
->offset
< r2
->offset
;
106 /* Returns true if RANGES contains any range that overlaps [OFFSET,
110 ranges_contain (VEC(range_s
) *ranges
, int offset
, int length
)
115 what
.offset
= offset
;
116 what
.length
= length
;
118 /* We keep ranges sorted by offset and coalesce overlapping and
119 contiguous ranges, so to check if a range list contains a given
120 range, we can do a binary search for the position the given range
121 would be inserted if we only considered the starting OFFSET of
122 ranges. We call that position I. Since we also have LENGTH to
123 care for (this is a range afterall), we need to check if the
124 _previous_ range overlaps the I range. E.g.,
128 |---| |---| |------| ... |--|
133 In the case above, the binary search would return `I=1', meaning,
134 this OFFSET should be inserted at position 1, and the current
135 position 1 should be pushed further (and before 2). But, `0'
138 Then we need to check if the I range overlaps the I range itself.
143 |---| |---| |-------| ... |--|
149 i
= VEC_lower_bound (range_s
, ranges
, &what
, range_lessthan
);
153 struct range
*bef
= VEC_index (range_s
, ranges
, i
- 1);
155 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
159 if (i
< VEC_length (range_s
, ranges
))
161 struct range
*r
= VEC_index (range_s
, ranges
, i
);
163 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
170 static struct cmd_list_element
*functionlist
;
172 /* Note that the fields in this structure are arranged to save a bit
177 /* Type of value; either not an lval, or one of the various
178 different possible kinds of lval. */
181 /* Is it modifiable? Only relevant if lval != not_lval. */
182 unsigned int modifiable
: 1;
184 /* If zero, contents of this value are in the contents field. If
185 nonzero, contents are in inferior. If the lval field is lval_memory,
186 the contents are in inferior memory at location.address plus offset.
187 The lval field may also be lval_register.
189 WARNING: This field is used by the code which handles watchpoints
190 (see breakpoint.c) to decide whether a particular value can be
191 watched by hardware watchpoints. If the lazy flag is set for
192 some member of a value chain, it is assumed that this member of
193 the chain doesn't need to be watched as part of watching the
194 value itself. This is how GDB avoids watching the entire struct
195 or array when the user wants to watch a single struct member or
196 array element. If you ever change the way lazy flag is set and
197 reset, be sure to consider this use as well! */
198 unsigned int lazy
: 1;
200 /* If nonzero, this is the value of a variable which does not
201 actually exist in the program. */
202 unsigned int optimized_out
: 1;
204 /* If value is a variable, is it initialized or not. */
205 unsigned int initialized
: 1;
207 /* If value is from the stack. If this is set, read_stack will be
208 used instead of read_memory to enable extra caching. */
209 unsigned int stack
: 1;
211 /* If the value has been released. */
212 unsigned int released
: 1;
214 /* Location of value (if lval). */
217 /* If lval == lval_memory, this is the address in the inferior.
218 If lval == lval_register, this is the byte offset into the
219 registers structure. */
222 /* Pointer to internal variable. */
223 struct internalvar
*internalvar
;
225 /* If lval == lval_computed, this is a set of function pointers
226 to use to access and describe the value, and a closure pointer
230 /* Functions to call. */
231 const struct lval_funcs
*funcs
;
233 /* Closure for those functions to use. */
238 /* Describes offset of a value within lval of a structure in bytes.
239 If lval == lval_memory, this is an offset to the address. If
240 lval == lval_register, this is a further offset from
241 location.address within the registers structure. Note also the
242 member embedded_offset below. */
245 /* Only used for bitfields; number of bits contained in them. */
248 /* Only used for bitfields; position of start of field. For
249 gdbarch_bits_big_endian=0 targets, it is the position of the LSB. For
250 gdbarch_bits_big_endian=1 targets, it is the position of the MSB. */
253 /* The number of references to this value. When a value is created,
254 the value chain holds a reference, so REFERENCE_COUNT is 1. If
255 release_value is called, this value is removed from the chain but
256 the caller of release_value now has a reference to this value.
257 The caller must arrange for a call to value_free later. */
260 /* Only used for bitfields; the containing value. This allows a
261 single read from the target when displaying multiple
263 struct value
*parent
;
265 /* Frame register value is relative to. This will be described in
266 the lval enum above as "lval_register". */
267 struct frame_id frame_id
;
269 /* Type of the value. */
272 /* If a value represents a C++ object, then the `type' field gives
273 the object's compile-time type. If the object actually belongs
274 to some class derived from `type', perhaps with other base
275 classes and additional members, then `type' is just a subobject
276 of the real thing, and the full object is probably larger than
277 `type' would suggest.
279 If `type' is a dynamic class (i.e. one with a vtable), then GDB
280 can actually determine the object's run-time type by looking at
281 the run-time type information in the vtable. When this
282 information is available, we may elect to read in the entire
283 object, for several reasons:
285 - When printing the value, the user would probably rather see the
286 full object, not just the limited portion apparent from the
289 - If `type' has virtual base classes, then even printing `type'
290 alone may require reaching outside the `type' portion of the
291 object to wherever the virtual base class has been stored.
293 When we store the entire object, `enclosing_type' is the run-time
294 type -- the complete object -- and `embedded_offset' is the
295 offset of `type' within that larger type, in bytes. The
296 value_contents() macro takes `embedded_offset' into account, so
297 most GDB code continues to see the `type' portion of the value,
298 just as the inferior would.
300 If `type' is a pointer to an object, then `enclosing_type' is a
301 pointer to the object's run-time type, and `pointed_to_offset' is
302 the offset in bytes from the full object to the pointed-to object
303 -- that is, the value `embedded_offset' would have if we followed
304 the pointer and fetched the complete object. (I don't really see
305 the point. Why not just determine the run-time type when you
306 indirect, and avoid the special case? The contents don't matter
307 until you indirect anyway.)
309 If we're not doing anything fancy, `enclosing_type' is equal to
310 `type', and `embedded_offset' is zero, so everything works
312 struct type
*enclosing_type
;
314 int pointed_to_offset
;
316 /* Values are stored in a chain, so that they can be deleted easily
317 over calls to the inferior. Values assigned to internal
318 variables, put into the value history or exposed to Python are
319 taken off this list. */
322 /* Register number if the value is from a register. */
325 /* Actual contents of the value. Target byte-order. NULL or not
326 valid if lazy is nonzero. */
329 /* Unavailable ranges in CONTENTS. We mark unavailable ranges,
330 rather than available, since the common and default case is for a
331 value to be available. This is filled in at value read time. */
332 VEC(range_s
) *unavailable
;
336 value_bytes_available (const struct value
*value
, int offset
, int length
)
338 gdb_assert (!value
->lazy
);
340 return !ranges_contain (value
->unavailable
, offset
, length
);
344 value_entirely_available (struct value
*value
)
346 /* We can only tell whether the whole value is available when we try
349 value_fetch_lazy (value
);
351 if (VEC_empty (range_s
, value
->unavailable
))
357 mark_value_bytes_unavailable (struct value
*value
, int offset
, int length
)
362 /* Insert the range sorted. If there's overlap or the new range
363 would be contiguous with an existing range, merge. */
365 newr
.offset
= offset
;
366 newr
.length
= length
;
368 /* Do a binary search for the position the given range would be
369 inserted if we only considered the starting OFFSET of ranges.
370 Call that position I. Since we also have LENGTH to care for
371 (this is a range afterall), we need to check if the _previous_
372 range overlaps the I range. E.g., calling R the new range:
374 #1 - overlaps with previous
378 |---| |---| |------| ... |--|
383 In the case #1 above, the binary search would return `I=1',
384 meaning, this OFFSET should be inserted at position 1, and the
385 current position 1 should be pushed further (and become 2). But,
386 note that `0' overlaps with R, so we want to merge them.
388 A similar consideration needs to be taken if the new range would
389 be contiguous with the previous range:
391 #2 - contiguous with previous
395 |--| |---| |------| ... |--|
400 If there's no overlap with the previous range, as in:
402 #3 - not overlapping and not contiguous
406 |--| |---| |------| ... |--|
413 #4 - R is the range with lowest offset
417 |--| |---| |------| ... |--|
422 ... we just push the new range to I.
424 All the 4 cases above need to consider that the new range may
425 also overlap several of the ranges that follow, or that R may be
426 contiguous with the following range, and merge. E.g.,
428 #5 - overlapping following ranges
431 |------------------------|
432 |--| |---| |------| ... |--|
441 |--| |---| |------| ... |--|
448 i
= VEC_lower_bound (range_s
, value
->unavailable
, &newr
, range_lessthan
);
451 struct range
*bef
= VEC_index (range_s
, value
->unavailable
, i
- 1);
453 if (ranges_overlap (bef
->offset
, bef
->length
, offset
, length
))
456 ULONGEST l
= min (bef
->offset
, offset
);
457 ULONGEST h
= max (bef
->offset
+ bef
->length
, offset
+ length
);
463 else if (offset
== bef
->offset
+ bef
->length
)
466 bef
->length
+= length
;
472 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
478 VEC_safe_insert (range_s
, value
->unavailable
, i
, &newr
);
481 /* Check whether the ranges following the one we've just added or
482 touched can be folded in (#5 above). */
483 if (i
+ 1 < VEC_length (range_s
, value
->unavailable
))
490 /* Get the range we just touched. */
491 t
= VEC_index (range_s
, value
->unavailable
, i
);
495 for (; VEC_iterate (range_s
, value
->unavailable
, i
, r
); i
++)
496 if (r
->offset
<= t
->offset
+ t
->length
)
500 l
= min (t
->offset
, r
->offset
);
501 h
= max (t
->offset
+ t
->length
, r
->offset
+ r
->length
);
510 /* If we couldn't merge this one, we won't be able to
511 merge following ones either, since the ranges are
512 always sorted by OFFSET. */
517 VEC_block_remove (range_s
, value
->unavailable
, next
, removed
);
521 /* Find the first range in RANGES that overlaps the range defined by
522 OFFSET and LENGTH, starting at element POS in the RANGES vector,
523 Returns the index into RANGES where such overlapping range was
524 found, or -1 if none was found. */
527 find_first_range_overlap (VEC(range_s
) *ranges
, int pos
,
528 int offset
, int length
)
533 for (i
= pos
; VEC_iterate (range_s
, ranges
, i
, r
); i
++)
534 if (ranges_overlap (r
->offset
, r
->length
, offset
, length
))
541 value_available_contents_eq (const struct value
*val1
, int offset1
,
542 const struct value
*val2
, int offset2
,
545 int idx1
= 0, idx2
= 0;
547 /* See function description in value.h. */
548 gdb_assert (!val1
->lazy
&& !val2
->lazy
);
556 idx1
= find_first_range_overlap (val1
->unavailable
, idx1
,
558 idx2
= find_first_range_overlap (val2
->unavailable
, idx2
,
561 /* The usual case is for both values to be completely available. */
562 if (idx1
== -1 && idx2
== -1)
563 return (memcmp (val1
->contents
+ offset1
,
564 val2
->contents
+ offset2
,
566 /* The contents only match equal if the available set matches as
568 else if (idx1
== -1 || idx2
== -1)
571 gdb_assert (idx1
!= -1 && idx2
!= -1);
573 r1
= VEC_index (range_s
, val1
->unavailable
, idx1
);
574 r2
= VEC_index (range_s
, val2
->unavailable
, idx2
);
576 /* Get the unavailable windows intersected by the incoming
577 ranges. The first and last ranges that overlap the argument
578 range may be wider than said incoming arguments ranges. */
579 l1
= max (offset1
, r1
->offset
);
580 h1
= min (offset1
+ length
, r1
->offset
+ r1
->length
);
582 l2
= max (offset2
, r2
->offset
);
583 h2
= min (offset2
+ length
, r2
->offset
+ r2
->length
);
585 /* Make them relative to the respective start offsets, so we can
586 compare them for equality. */
593 /* Different availability, no match. */
594 if (l1
!= l2
|| h1
!= h2
)
597 /* Compare the _available_ contents. */
598 if (memcmp (val1
->contents
+ offset1
,
599 val2
->contents
+ offset2
,
611 /* Prototypes for local functions. */
613 static void show_values (char *, int);
615 static void show_convenience (char *, int);
618 /* The value-history records all the values printed
619 by print commands during this session. Each chunk
620 records 60 consecutive values. The first chunk on
621 the chain records the most recent values.
622 The total number of values is in value_history_count. */
624 #define VALUE_HISTORY_CHUNK 60
626 struct value_history_chunk
628 struct value_history_chunk
*next
;
629 struct value
*values
[VALUE_HISTORY_CHUNK
];
632 /* Chain of chunks now in use. */
634 static struct value_history_chunk
*value_history_chain
;
636 static int value_history_count
; /* Abs number of last entry stored. */
639 /* List of all value objects currently allocated
640 (except for those released by calls to release_value)
641 This is so they can be freed after each command. */
643 static struct value
*all_values
;
645 /* Allocate a lazy value for type TYPE. Its actual content is
646 "lazily" allocated too: the content field of the return value is
647 NULL; it will be allocated when it is fetched from the target. */
650 allocate_value_lazy (struct type
*type
)
654 /* Call check_typedef on our type to make sure that, if TYPE
655 is a TYPE_CODE_TYPEDEF, its length is set to the length
656 of the target type instead of zero. However, we do not
657 replace the typedef type by the target type, because we want
658 to keep the typedef in order to be able to set the VAL's type
659 description correctly. */
660 check_typedef (type
);
662 val
= (struct value
*) xzalloc (sizeof (struct value
));
663 val
->contents
= NULL
;
664 val
->next
= all_values
;
667 val
->enclosing_type
= type
;
668 VALUE_LVAL (val
) = not_lval
;
669 val
->location
.address
= 0;
670 VALUE_FRAME_ID (val
) = null_frame_id
;
674 VALUE_REGNUM (val
) = -1;
676 val
->optimized_out
= 0;
677 val
->embedded_offset
= 0;
678 val
->pointed_to_offset
= 0;
680 val
->initialized
= 1; /* Default to initialized. */
682 /* Values start out on the all_values chain. */
683 val
->reference_count
= 1;
688 /* Allocate the contents of VAL if it has not been allocated yet. */
691 allocate_value_contents (struct value
*val
)
694 val
->contents
= (gdb_byte
*) xzalloc (TYPE_LENGTH (val
->enclosing_type
));
697 /* Allocate a value and its contents for type TYPE. */
700 allocate_value (struct type
*type
)
702 struct value
*val
= allocate_value_lazy (type
);
704 allocate_value_contents (val
);
709 /* Allocate a value that has the correct length
710 for COUNT repetitions of type TYPE. */
713 allocate_repeat_value (struct type
*type
, int count
)
715 int low_bound
= current_language
->string_lower_bound
; /* ??? */
716 /* FIXME-type-allocation: need a way to free this type when we are
718 struct type
*array_type
719 = lookup_array_range_type (type
, low_bound
, count
+ low_bound
- 1);
721 return allocate_value (array_type
);
725 allocate_computed_value (struct type
*type
,
726 const struct lval_funcs
*funcs
,
729 struct value
*v
= allocate_value_lazy (type
);
731 VALUE_LVAL (v
) = lval_computed
;
732 v
->location
.computed
.funcs
= funcs
;
733 v
->location
.computed
.closure
= closure
;
738 /* Allocate NOT_LVAL value for type TYPE being OPTIMIZED_OUT. */
741 allocate_optimized_out_value (struct type
*type
)
743 struct value
*retval
= allocate_value_lazy (type
);
745 set_value_optimized_out (retval
, 1);
750 /* Accessor methods. */
753 value_next (struct value
*value
)
759 value_type (const struct value
*value
)
764 deprecated_set_value_type (struct value
*value
, struct type
*type
)
770 value_offset (const struct value
*value
)
772 return value
->offset
;
775 set_value_offset (struct value
*value
, int offset
)
777 value
->offset
= offset
;
781 value_bitpos (const struct value
*value
)
783 return value
->bitpos
;
786 set_value_bitpos (struct value
*value
, int bit
)
792 value_bitsize (const struct value
*value
)
794 return value
->bitsize
;
797 set_value_bitsize (struct value
*value
, int bit
)
799 value
->bitsize
= bit
;
803 value_parent (struct value
*value
)
805 return value
->parent
;
811 set_value_parent (struct value
*value
, struct value
*parent
)
813 struct value
*old
= value
->parent
;
815 value
->parent
= parent
;
817 value_incref (parent
);
822 value_contents_raw (struct value
*value
)
824 allocate_value_contents (value
);
825 return value
->contents
+ value
->embedded_offset
;
829 value_contents_all_raw (struct value
*value
)
831 allocate_value_contents (value
);
832 return value
->contents
;
836 value_enclosing_type (struct value
*value
)
838 return value
->enclosing_type
;
841 /* Look at value.h for description. */
844 value_actual_type (struct value
*value
, int resolve_simple_types
,
845 int *real_type_found
)
847 struct value_print_options opts
;
850 get_user_print_options (&opts
);
853 *real_type_found
= 0;
854 result
= value_type (value
);
855 if (opts
.objectprint
)
857 /* If result's target type is TYPE_CODE_STRUCT, proceed to
858 fetch its rtti type. */
859 if ((TYPE_CODE (result
) == TYPE_CODE_PTR
860 || TYPE_CODE (result
) == TYPE_CODE_REF
)
861 && TYPE_CODE (check_typedef (TYPE_TARGET_TYPE (result
)))
864 struct type
*real_type
;
866 real_type
= value_rtti_indirect_type (value
, NULL
, NULL
, NULL
);
870 *real_type_found
= 1;
874 else if (resolve_simple_types
)
877 *real_type_found
= 1;
878 result
= value_enclosing_type (value
);
886 require_not_optimized_out (const struct value
*value
)
888 if (value
->optimized_out
)
889 error (_("value has been optimized out"));
893 require_available (const struct value
*value
)
895 if (!VEC_empty (range_s
, value
->unavailable
))
896 throw_error (NOT_AVAILABLE_ERROR
, _("value is not available"));
900 value_contents_for_printing (struct value
*value
)
903 value_fetch_lazy (value
);
904 return value
->contents
;
908 value_contents_for_printing_const (const struct value
*value
)
910 gdb_assert (!value
->lazy
);
911 return value
->contents
;
915 value_contents_all (struct value
*value
)
917 const gdb_byte
*result
= value_contents_for_printing (value
);
918 require_not_optimized_out (value
);
919 require_available (value
);
923 /* Copy LENGTH bytes of SRC value's (all) contents
924 (value_contents_all) starting at SRC_OFFSET, into DST value's (all)
925 contents, starting at DST_OFFSET. If unavailable contents are
926 being copied from SRC, the corresponding DST contents are marked
927 unavailable accordingly. Neither DST nor SRC may be lazy
930 It is assumed the contents of DST in the [DST_OFFSET,
931 DST_OFFSET+LENGTH) range are wholly available. */
934 value_contents_copy_raw (struct value
*dst
, int dst_offset
,
935 struct value
*src
, int src_offset
, int length
)
940 /* A lazy DST would make that this copy operation useless, since as
941 soon as DST's contents were un-lazied (by a later value_contents
942 call, say), the contents would be overwritten. A lazy SRC would
943 mean we'd be copying garbage. */
944 gdb_assert (!dst
->lazy
&& !src
->lazy
);
946 /* The overwritten DST range gets unavailability ORed in, not
947 replaced. Make sure to remember to implement replacing if it
948 turns out actually necessary. */
949 gdb_assert (value_bytes_available (dst
, dst_offset
, length
));
952 memcpy (value_contents_all_raw (dst
) + dst_offset
,
953 value_contents_all_raw (src
) + src_offset
,
956 /* Copy the meta-data, adjusted. */
957 for (i
= 0; VEC_iterate (range_s
, src
->unavailable
, i
, r
); i
++)
961 l
= max (r
->offset
, src_offset
);
962 h
= min (r
->offset
+ r
->length
, src_offset
+ length
);
965 mark_value_bytes_unavailable (dst
,
966 dst_offset
+ (l
- src_offset
),
971 /* Copy LENGTH bytes of SRC value's (all) contents
972 (value_contents_all) starting at SRC_OFFSET byte, into DST value's
973 (all) contents, starting at DST_OFFSET. If unavailable contents
974 are being copied from SRC, the corresponding DST contents are
975 marked unavailable accordingly. DST must not be lazy. If SRC is
976 lazy, it will be fetched now. If SRC is not valid (is optimized
977 out), an error is thrown.
979 It is assumed the contents of DST in the [DST_OFFSET,
980 DST_OFFSET+LENGTH) range are wholly available. */
983 value_contents_copy (struct value
*dst
, int dst_offset
,
984 struct value
*src
, int src_offset
, int length
)
986 require_not_optimized_out (src
);
989 value_fetch_lazy (src
);
991 value_contents_copy_raw (dst
, dst_offset
, src
, src_offset
, length
);
995 value_lazy (struct value
*value
)
1001 set_value_lazy (struct value
*value
, int val
)
1007 value_stack (struct value
*value
)
1009 return value
->stack
;
1013 set_value_stack (struct value
*value
, int val
)
1019 value_contents (struct value
*value
)
1021 const gdb_byte
*result
= value_contents_writeable (value
);
1022 require_not_optimized_out (value
);
1023 require_available (value
);
1028 value_contents_writeable (struct value
*value
)
1031 value_fetch_lazy (value
);
1032 return value_contents_raw (value
);
1035 /* Return non-zero if VAL1 and VAL2 have the same contents. Note that
1036 this function is different from value_equal; in C the operator ==
1037 can return 0 even if the two values being compared are equal. */
1040 value_contents_equal (struct value
*val1
, struct value
*val2
)
1045 type1
= check_typedef (value_type (val1
));
1046 type2
= check_typedef (value_type (val2
));
1047 if (TYPE_LENGTH (type1
) != TYPE_LENGTH (type2
))
1050 return (memcmp (value_contents (val1
), value_contents (val2
),
1051 TYPE_LENGTH (type1
)) == 0);
1055 value_optimized_out (struct value
*value
)
1057 /* We can only know if a value is optimized out once we have tried to
1059 if (!value
->optimized_out
&& value
->lazy
)
1060 value_fetch_lazy (value
);
1062 return value
->optimized_out
;
1066 set_value_optimized_out (struct value
*value
, int val
)
1068 value
->optimized_out
= val
;
1072 value_entirely_optimized_out (const struct value
*value
)
1074 if (!value
->optimized_out
)
1076 if (value
->lval
!= lval_computed
1077 || !value
->location
.computed
.funcs
->check_any_valid
)
1079 return !value
->location
.computed
.funcs
->check_any_valid (value
);
1083 value_bits_valid (const struct value
*value
, int offset
, int length
)
1085 if (value
->lval
!= lval_computed
1086 || !value
->location
.computed
.funcs
->check_validity
)
1087 return !value
->optimized_out
;
1089 return value
->location
.computed
.funcs
->check_validity (value
, offset
,
1094 value_bits_synthetic_pointer (const struct value
*value
,
1095 int offset
, int length
)
1097 if (value
->lval
!= lval_computed
1098 || !value
->location
.computed
.funcs
->check_synthetic_pointer
)
1100 return value
->location
.computed
.funcs
->check_synthetic_pointer (value
,
1106 value_embedded_offset (struct value
*value
)
1108 return value
->embedded_offset
;
1112 set_value_embedded_offset (struct value
*value
, int val
)
1114 value
->embedded_offset
= val
;
1118 value_pointed_to_offset (struct value
*value
)
1120 return value
->pointed_to_offset
;
1124 set_value_pointed_to_offset (struct value
*value
, int val
)
1126 value
->pointed_to_offset
= val
;
1129 const struct lval_funcs
*
1130 value_computed_funcs (const struct value
*v
)
1132 gdb_assert (value_lval_const (v
) == lval_computed
);
1134 return v
->location
.computed
.funcs
;
1138 value_computed_closure (const struct value
*v
)
1140 gdb_assert (v
->lval
== lval_computed
);
1142 return v
->location
.computed
.closure
;
1146 deprecated_value_lval_hack (struct value
*value
)
1148 return &value
->lval
;
1152 value_lval_const (const struct value
*value
)
1158 value_address (const struct value
*value
)
1160 if (value
->lval
== lval_internalvar
1161 || value
->lval
== lval_internalvar_component
)
1163 if (value
->parent
!= NULL
)
1164 return value_address (value
->parent
) + value
->offset
;
1166 return value
->location
.address
+ value
->offset
;
1170 value_raw_address (struct value
*value
)
1172 if (value
->lval
== lval_internalvar
1173 || value
->lval
== lval_internalvar_component
)
1175 return value
->location
.address
;
1179 set_value_address (struct value
*value
, CORE_ADDR addr
)
1181 gdb_assert (value
->lval
!= lval_internalvar
1182 && value
->lval
!= lval_internalvar_component
);
1183 value
->location
.address
= addr
;
1186 struct internalvar
**
1187 deprecated_value_internalvar_hack (struct value
*value
)
1189 return &value
->location
.internalvar
;
1193 deprecated_value_frame_id_hack (struct value
*value
)
1195 return &value
->frame_id
;
1199 deprecated_value_regnum_hack (struct value
*value
)
1201 return &value
->regnum
;
1205 deprecated_value_modifiable (struct value
*value
)
1207 return value
->modifiable
;
1210 /* Return a mark in the value chain. All values allocated after the
1211 mark is obtained (except for those released) are subject to being freed
1212 if a subsequent value_free_to_mark is passed the mark. */
1219 /* Take a reference to VAL. VAL will not be deallocated until all
1220 references are released. */
1223 value_incref (struct value
*val
)
1225 val
->reference_count
++;
1228 /* Release a reference to VAL, which was acquired with value_incref.
1229 This function is also called to deallocate values from the value
1233 value_free (struct value
*val
)
1237 gdb_assert (val
->reference_count
> 0);
1238 val
->reference_count
--;
1239 if (val
->reference_count
> 0)
1242 /* If there's an associated parent value, drop our reference to
1244 if (val
->parent
!= NULL
)
1245 value_free (val
->parent
);
1247 if (VALUE_LVAL (val
) == lval_computed
)
1249 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1251 if (funcs
->free_closure
)
1252 funcs
->free_closure (val
);
1255 xfree (val
->contents
);
1256 VEC_free (range_s
, val
->unavailable
);
1261 /* Free all values allocated since MARK was obtained by value_mark
1262 (except for those released). */
1264 value_free_to_mark (struct value
*mark
)
1269 for (val
= all_values
; val
&& val
!= mark
; val
= next
)
1278 /* Free all the values that have been allocated (except for those released).
1279 Call after each command, successful or not.
1280 In practice this is called before each command, which is sufficient. */
1283 free_all_values (void)
1288 for (val
= all_values
; val
; val
= next
)
1298 /* Frees all the elements in a chain of values. */
1301 free_value_chain (struct value
*v
)
1307 next
= value_next (v
);
1312 /* Remove VAL from the chain all_values
1313 so it will not be freed automatically. */
1316 release_value (struct value
*val
)
1320 if (all_values
== val
)
1322 all_values
= val
->next
;
1328 for (v
= all_values
; v
; v
= v
->next
)
1332 v
->next
= val
->next
;
1340 /* If the value is not already released, release it.
1341 If the value is already released, increment its reference count.
1342 That is, this function ensures that the value is released from the
1343 value chain and that the caller owns a reference to it. */
1346 release_value_or_incref (struct value
*val
)
1351 release_value (val
);
1354 /* Release all values up to mark */
1356 value_release_to_mark (struct value
*mark
)
1361 for (val
= next
= all_values
; next
; next
= next
->next
)
1363 if (next
->next
== mark
)
1365 all_values
= next
->next
;
1375 /* Return a copy of the value ARG.
1376 It contains the same contents, for same memory address,
1377 but it's a different block of storage. */
1380 value_copy (struct value
*arg
)
1382 struct type
*encl_type
= value_enclosing_type (arg
);
1385 if (value_lazy (arg
))
1386 val
= allocate_value_lazy (encl_type
);
1388 val
= allocate_value (encl_type
);
1389 val
->type
= arg
->type
;
1390 VALUE_LVAL (val
) = VALUE_LVAL (arg
);
1391 val
->location
= arg
->location
;
1392 val
->offset
= arg
->offset
;
1393 val
->bitpos
= arg
->bitpos
;
1394 val
->bitsize
= arg
->bitsize
;
1395 VALUE_FRAME_ID (val
) = VALUE_FRAME_ID (arg
);
1396 VALUE_REGNUM (val
) = VALUE_REGNUM (arg
);
1397 val
->lazy
= arg
->lazy
;
1398 val
->optimized_out
= arg
->optimized_out
;
1399 val
->embedded_offset
= value_embedded_offset (arg
);
1400 val
->pointed_to_offset
= arg
->pointed_to_offset
;
1401 val
->modifiable
= arg
->modifiable
;
1402 if (!value_lazy (val
))
1404 memcpy (value_contents_all_raw (val
), value_contents_all_raw (arg
),
1405 TYPE_LENGTH (value_enclosing_type (arg
)));
1408 val
->unavailable
= VEC_copy (range_s
, arg
->unavailable
);
1409 set_value_parent (val
, arg
->parent
);
1410 if (VALUE_LVAL (val
) == lval_computed
)
1412 const struct lval_funcs
*funcs
= val
->location
.computed
.funcs
;
1414 if (funcs
->copy_closure
)
1415 val
->location
.computed
.closure
= funcs
->copy_closure (val
);
1420 /* Return a version of ARG that is non-lvalue. */
1423 value_non_lval (struct value
*arg
)
1425 if (VALUE_LVAL (arg
) != not_lval
)
1427 struct type
*enc_type
= value_enclosing_type (arg
);
1428 struct value
*val
= allocate_value (enc_type
);
1430 memcpy (value_contents_all_raw (val
), value_contents_all (arg
),
1431 TYPE_LENGTH (enc_type
));
1432 val
->type
= arg
->type
;
1433 set_value_embedded_offset (val
, value_embedded_offset (arg
));
1434 set_value_pointed_to_offset (val
, value_pointed_to_offset (arg
));
1441 set_value_component_location (struct value
*component
,
1442 const struct value
*whole
)
1444 if (whole
->lval
== lval_internalvar
)
1445 VALUE_LVAL (component
) = lval_internalvar_component
;
1447 VALUE_LVAL (component
) = whole
->lval
;
1449 component
->location
= whole
->location
;
1450 if (whole
->lval
== lval_computed
)
1452 const struct lval_funcs
*funcs
= whole
->location
.computed
.funcs
;
1454 if (funcs
->copy_closure
)
1455 component
->location
.computed
.closure
= funcs
->copy_closure (whole
);
1460 /* Access to the value history. */
1462 /* Record a new value in the value history.
1463 Returns the absolute history index of the entry.
1464 Result of -1 indicates the value was not saved; otherwise it is the
1465 value history index of this new item. */
1468 record_latest_value (struct value
*val
)
1472 /* We don't want this value to have anything to do with the inferior anymore.
1473 In particular, "set $1 = 50" should not affect the variable from which
1474 the value was taken, and fast watchpoints should be able to assume that
1475 a value on the value history never changes. */
1476 if (value_lazy (val
))
1477 value_fetch_lazy (val
);
1478 /* We preserve VALUE_LVAL so that the user can find out where it was fetched
1479 from. This is a bit dubious, because then *&$1 does not just return $1
1480 but the current contents of that location. c'est la vie... */
1481 val
->modifiable
= 0;
1482 release_value (val
);
1484 /* Here we treat value_history_count as origin-zero
1485 and applying to the value being stored now. */
1487 i
= value_history_count
% VALUE_HISTORY_CHUNK
;
1490 struct value_history_chunk
*new
1491 = (struct value_history_chunk
*)
1493 xmalloc (sizeof (struct value_history_chunk
));
1494 memset (new->values
, 0, sizeof new->values
);
1495 new->next
= value_history_chain
;
1496 value_history_chain
= new;
1499 value_history_chain
->values
[i
] = val
;
1501 /* Now we regard value_history_count as origin-one
1502 and applying to the value just stored. */
1504 return ++value_history_count
;
1507 /* Return a copy of the value in the history with sequence number NUM. */
1510 access_value_history (int num
)
1512 struct value_history_chunk
*chunk
;
1517 absnum
+= value_history_count
;
1522 error (_("The history is empty."));
1524 error (_("There is only one value in the history."));
1526 error (_("History does not go back to $$%d."), -num
);
1528 if (absnum
> value_history_count
)
1529 error (_("History has not yet reached $%d."), absnum
);
1533 /* Now absnum is always absolute and origin zero. */
1535 chunk
= value_history_chain
;
1536 for (i
= (value_history_count
- 1) / VALUE_HISTORY_CHUNK
1537 - absnum
/ VALUE_HISTORY_CHUNK
;
1539 chunk
= chunk
->next
;
1541 return value_copy (chunk
->values
[absnum
% VALUE_HISTORY_CHUNK
]);
1545 show_values (char *num_exp
, int from_tty
)
1553 /* "show values +" should print from the stored position.
1554 "show values <exp>" should print around value number <exp>. */
1555 if (num_exp
[0] != '+' || num_exp
[1] != '\0')
1556 num
= parse_and_eval_long (num_exp
) - 5;
1560 /* "show values" means print the last 10 values. */
1561 num
= value_history_count
- 9;
1567 for (i
= num
; i
< num
+ 10 && i
<= value_history_count
; i
++)
1569 struct value_print_options opts
;
1571 val
= access_value_history (i
);
1572 printf_filtered (("$%d = "), i
);
1573 get_user_print_options (&opts
);
1574 value_print (val
, gdb_stdout
, &opts
);
1575 printf_filtered (("\n"));
1578 /* The next "show values +" should start after what we just printed. */
1581 /* Hitting just return after this command should do the same thing as
1582 "show values +". If num_exp is null, this is unnecessary, since
1583 "show values +" is not useful after "show values". */
1584 if (from_tty
&& num_exp
)
1591 /* Internal variables. These are variables within the debugger
1592 that hold values assigned by debugger commands.
1593 The user refers to them with a '$' prefix
1594 that does not appear in the variable names stored internally. */
1598 struct internalvar
*next
;
1601 /* We support various different kinds of content of an internal variable.
1602 enum internalvar_kind specifies the kind, and union internalvar_data
1603 provides the data associated with this particular kind. */
1605 enum internalvar_kind
1607 /* The internal variable is empty. */
1610 /* The value of the internal variable is provided directly as
1611 a GDB value object. */
1614 /* A fresh value is computed via a call-back routine on every
1615 access to the internal variable. */
1616 INTERNALVAR_MAKE_VALUE
,
1618 /* The internal variable holds a GDB internal convenience function. */
1619 INTERNALVAR_FUNCTION
,
1621 /* The variable holds an integer value. */
1622 INTERNALVAR_INTEGER
,
1624 /* The variable holds a GDB-provided string. */
1629 union internalvar_data
1631 /* A value object used with INTERNALVAR_VALUE. */
1632 struct value
*value
;
1634 /* The call-back routine used with INTERNALVAR_MAKE_VALUE. */
1637 /* The functions to call. */
1638 const struct internalvar_funcs
*functions
;
1640 /* The function's user-data. */
1644 /* The internal function used with INTERNALVAR_FUNCTION. */
1647 struct internal_function
*function
;
1648 /* True if this is the canonical name for the function. */
1652 /* An integer value used with INTERNALVAR_INTEGER. */
1655 /* If type is non-NULL, it will be used as the type to generate
1656 a value for this internal variable. If type is NULL, a default
1657 integer type for the architecture is used. */
1662 /* A string value used with INTERNALVAR_STRING. */
1667 static struct internalvar
*internalvars
;
1669 /* If the variable does not already exist create it and give it the
1670 value given. If no value is given then the default is zero. */
1672 init_if_undefined_command (char* args
, int from_tty
)
1674 struct internalvar
* intvar
;
1676 /* Parse the expression - this is taken from set_command(). */
1677 struct expression
*expr
= parse_expression (args
);
1678 register struct cleanup
*old_chain
=
1679 make_cleanup (free_current_contents
, &expr
);
1681 /* Validate the expression.
1682 Was the expression an assignment?
1683 Or even an expression at all? */
1684 if (expr
->nelts
== 0 || expr
->elts
[0].opcode
!= BINOP_ASSIGN
)
1685 error (_("Init-if-undefined requires an assignment expression."));
1687 /* Extract the variable from the parsed expression.
1688 In the case of an assign the lvalue will be in elts[1] and elts[2]. */
1689 if (expr
->elts
[1].opcode
!= OP_INTERNALVAR
)
1690 error (_("The first parameter to init-if-undefined "
1691 "should be a GDB variable."));
1692 intvar
= expr
->elts
[2].internalvar
;
1694 /* Only evaluate the expression if the lvalue is void.
1695 This may still fail if the expresssion is invalid. */
1696 if (intvar
->kind
== INTERNALVAR_VOID
)
1697 evaluate_expression (expr
);
1699 do_cleanups (old_chain
);
1703 /* Look up an internal variable with name NAME. NAME should not
1704 normally include a dollar sign.
1706 If the specified internal variable does not exist,
1707 the return value is NULL. */
1709 struct internalvar
*
1710 lookup_only_internalvar (const char *name
)
1712 struct internalvar
*var
;
1714 for (var
= internalvars
; var
; var
= var
->next
)
1715 if (strcmp (var
->name
, name
) == 0)
1721 /* Complete NAME by comparing it to the names of internal variables.
1722 Returns a vector of newly allocated strings, or NULL if no matches
1726 complete_internalvar (const char *name
)
1728 VEC (char_ptr
) *result
= NULL
;
1729 struct internalvar
*var
;
1732 len
= strlen (name
);
1734 for (var
= internalvars
; var
; var
= var
->next
)
1735 if (strncmp (var
->name
, name
, len
) == 0)
1737 char *r
= xstrdup (var
->name
);
1739 VEC_safe_push (char_ptr
, result
, r
);
1745 /* Create an internal variable with name NAME and with a void value.
1746 NAME should not normally include a dollar sign. */
1748 struct internalvar
*
1749 create_internalvar (const char *name
)
1751 struct internalvar
*var
;
1753 var
= (struct internalvar
*) xmalloc (sizeof (struct internalvar
));
1754 var
->name
= concat (name
, (char *)NULL
);
1755 var
->kind
= INTERNALVAR_VOID
;
1756 var
->next
= internalvars
;
1761 /* Create an internal variable with name NAME and register FUN as the
1762 function that value_of_internalvar uses to create a value whenever
1763 this variable is referenced. NAME should not normally include a
1764 dollar sign. DATA is passed uninterpreted to FUN when it is
1765 called. CLEANUP, if not NULL, is called when the internal variable
1766 is destroyed. It is passed DATA as its only argument. */
1768 struct internalvar
*
1769 create_internalvar_type_lazy (const char *name
,
1770 const struct internalvar_funcs
*funcs
,
1773 struct internalvar
*var
= create_internalvar (name
);
1775 var
->kind
= INTERNALVAR_MAKE_VALUE
;
1776 var
->u
.make_value
.functions
= funcs
;
1777 var
->u
.make_value
.data
= data
;
1781 /* See documentation in value.h. */
1784 compile_internalvar_to_ax (struct internalvar
*var
,
1785 struct agent_expr
*expr
,
1786 struct axs_value
*value
)
1788 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1789 || var
->u
.make_value
.functions
->compile_to_ax
== NULL
)
1792 var
->u
.make_value
.functions
->compile_to_ax (var
, expr
, value
,
1793 var
->u
.make_value
.data
);
1797 /* Look up an internal variable with name NAME. NAME should not
1798 normally include a dollar sign.
1800 If the specified internal variable does not exist,
1801 one is created, with a void value. */
1803 struct internalvar
*
1804 lookup_internalvar (const char *name
)
1806 struct internalvar
*var
;
1808 var
= lookup_only_internalvar (name
);
1812 return create_internalvar (name
);
1815 /* Return current value of internal variable VAR. For variables that
1816 are not inherently typed, use a value type appropriate for GDBARCH. */
1819 value_of_internalvar (struct gdbarch
*gdbarch
, struct internalvar
*var
)
1822 struct trace_state_variable
*tsv
;
1824 /* If there is a trace state variable of the same name, assume that
1825 is what we really want to see. */
1826 tsv
= find_trace_state_variable (var
->name
);
1829 tsv
->value_known
= target_get_trace_state_variable_value (tsv
->number
,
1831 if (tsv
->value_known
)
1832 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int64
,
1835 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1841 case INTERNALVAR_VOID
:
1842 val
= allocate_value (builtin_type (gdbarch
)->builtin_void
);
1845 case INTERNALVAR_FUNCTION
:
1846 val
= allocate_value (builtin_type (gdbarch
)->internal_fn
);
1849 case INTERNALVAR_INTEGER
:
1850 if (!var
->u
.integer
.type
)
1851 val
= value_from_longest (builtin_type (gdbarch
)->builtin_int
,
1852 var
->u
.integer
.val
);
1854 val
= value_from_longest (var
->u
.integer
.type
, var
->u
.integer
.val
);
1857 case INTERNALVAR_STRING
:
1858 val
= value_cstring (var
->u
.string
, strlen (var
->u
.string
),
1859 builtin_type (gdbarch
)->builtin_char
);
1862 case INTERNALVAR_VALUE
:
1863 val
= value_copy (var
->u
.value
);
1864 if (value_lazy (val
))
1865 value_fetch_lazy (val
);
1868 case INTERNALVAR_MAKE_VALUE
:
1869 val
= (*var
->u
.make_value
.functions
->make_value
) (gdbarch
, var
,
1870 var
->u
.make_value
.data
);
1874 internal_error (__FILE__
, __LINE__
, _("bad kind"));
1877 /* Change the VALUE_LVAL to lval_internalvar so that future operations
1878 on this value go back to affect the original internal variable.
1880 Do not do this for INTERNALVAR_MAKE_VALUE variables, as those have
1881 no underlying modifyable state in the internal variable.
1883 Likewise, if the variable's value is a computed lvalue, we want
1884 references to it to produce another computed lvalue, where
1885 references and assignments actually operate through the
1886 computed value's functions.
1888 This means that internal variables with computed values
1889 behave a little differently from other internal variables:
1890 assignments to them don't just replace the previous value
1891 altogether. At the moment, this seems like the behavior we
1894 if (var
->kind
!= INTERNALVAR_MAKE_VALUE
1895 && val
->lval
!= lval_computed
)
1897 VALUE_LVAL (val
) = lval_internalvar
;
1898 VALUE_INTERNALVAR (val
) = var
;
1905 get_internalvar_integer (struct internalvar
*var
, LONGEST
*result
)
1907 if (var
->kind
== INTERNALVAR_INTEGER
)
1909 *result
= var
->u
.integer
.val
;
1913 if (var
->kind
== INTERNALVAR_VALUE
)
1915 struct type
*type
= check_typedef (value_type (var
->u
.value
));
1917 if (TYPE_CODE (type
) == TYPE_CODE_INT
)
1919 *result
= value_as_long (var
->u
.value
);
1928 get_internalvar_function (struct internalvar
*var
,
1929 struct internal_function
**result
)
1933 case INTERNALVAR_FUNCTION
:
1934 *result
= var
->u
.fn
.function
;
1943 set_internalvar_component (struct internalvar
*var
, int offset
, int bitpos
,
1944 int bitsize
, struct value
*newval
)
1950 case INTERNALVAR_VALUE
:
1951 addr
= value_contents_writeable (var
->u
.value
);
1954 modify_field (value_type (var
->u
.value
), addr
+ offset
,
1955 value_as_long (newval
), bitpos
, bitsize
);
1957 memcpy (addr
+ offset
, value_contents (newval
),
1958 TYPE_LENGTH (value_type (newval
)));
1962 /* We can never get a component of any other kind. */
1963 internal_error (__FILE__
, __LINE__
, _("set_internalvar_component"));
1968 set_internalvar (struct internalvar
*var
, struct value
*val
)
1970 enum internalvar_kind new_kind
;
1971 union internalvar_data new_data
= { 0 };
1973 if (var
->kind
== INTERNALVAR_FUNCTION
&& var
->u
.fn
.canonical
)
1974 error (_("Cannot overwrite convenience function %s"), var
->name
);
1976 /* Prepare new contents. */
1977 switch (TYPE_CODE (check_typedef (value_type (val
))))
1979 case TYPE_CODE_VOID
:
1980 new_kind
= INTERNALVAR_VOID
;
1983 case TYPE_CODE_INTERNAL_FUNCTION
:
1984 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
1985 new_kind
= INTERNALVAR_FUNCTION
;
1986 get_internalvar_function (VALUE_INTERNALVAR (val
),
1987 &new_data
.fn
.function
);
1988 /* Copies created here are never canonical. */
1992 new_kind
= INTERNALVAR_VALUE
;
1993 new_data
.value
= value_copy (val
);
1994 new_data
.value
->modifiable
= 1;
1996 /* Force the value to be fetched from the target now, to avoid problems
1997 later when this internalvar is referenced and the target is gone or
1999 if (value_lazy (new_data
.value
))
2000 value_fetch_lazy (new_data
.value
);
2002 /* Release the value from the value chain to prevent it from being
2003 deleted by free_all_values. From here on this function should not
2004 call error () until new_data is installed into the var->u to avoid
2006 release_value (new_data
.value
);
2010 /* Clean up old contents. */
2011 clear_internalvar (var
);
2014 var
->kind
= new_kind
;
2016 /* End code which must not call error(). */
2020 set_internalvar_integer (struct internalvar
*var
, LONGEST l
)
2022 /* Clean up old contents. */
2023 clear_internalvar (var
);
2025 var
->kind
= INTERNALVAR_INTEGER
;
2026 var
->u
.integer
.type
= NULL
;
2027 var
->u
.integer
.val
= l
;
2031 set_internalvar_string (struct internalvar
*var
, const char *string
)
2033 /* Clean up old contents. */
2034 clear_internalvar (var
);
2036 var
->kind
= INTERNALVAR_STRING
;
2037 var
->u
.string
= xstrdup (string
);
2041 set_internalvar_function (struct internalvar
*var
, struct internal_function
*f
)
2043 /* Clean up old contents. */
2044 clear_internalvar (var
);
2046 var
->kind
= INTERNALVAR_FUNCTION
;
2047 var
->u
.fn
.function
= f
;
2048 var
->u
.fn
.canonical
= 1;
2049 /* Variables installed here are always the canonical version. */
2053 clear_internalvar (struct internalvar
*var
)
2055 /* Clean up old contents. */
2058 case INTERNALVAR_VALUE
:
2059 value_free (var
->u
.value
);
2062 case INTERNALVAR_STRING
:
2063 xfree (var
->u
.string
);
2066 case INTERNALVAR_MAKE_VALUE
:
2067 if (var
->u
.make_value
.functions
->destroy
!= NULL
)
2068 var
->u
.make_value
.functions
->destroy (var
->u
.make_value
.data
);
2075 /* Reset to void kind. */
2076 var
->kind
= INTERNALVAR_VOID
;
2080 internalvar_name (struct internalvar
*var
)
2085 static struct internal_function
*
2086 create_internal_function (const char *name
,
2087 internal_function_fn handler
, void *cookie
)
2089 struct internal_function
*ifn
= XNEW (struct internal_function
);
2091 ifn
->name
= xstrdup (name
);
2092 ifn
->handler
= handler
;
2093 ifn
->cookie
= cookie
;
2098 value_internal_function_name (struct value
*val
)
2100 struct internal_function
*ifn
;
2103 gdb_assert (VALUE_LVAL (val
) == lval_internalvar
);
2104 result
= get_internalvar_function (VALUE_INTERNALVAR (val
), &ifn
);
2105 gdb_assert (result
);
2111 call_internal_function (struct gdbarch
*gdbarch
,
2112 const struct language_defn
*language
,
2113 struct value
*func
, int argc
, struct value
**argv
)
2115 struct internal_function
*ifn
;
2118 gdb_assert (VALUE_LVAL (func
) == lval_internalvar
);
2119 result
= get_internalvar_function (VALUE_INTERNALVAR (func
), &ifn
);
2120 gdb_assert (result
);
2122 return (*ifn
->handler
) (gdbarch
, language
, ifn
->cookie
, argc
, argv
);
2125 /* The 'function' command. This does nothing -- it is just a
2126 placeholder to let "help function NAME" work. This is also used as
2127 the implementation of the sub-command that is created when
2128 registering an internal function. */
2130 function_command (char *command
, int from_tty
)
2135 /* Clean up if an internal function's command is destroyed. */
2137 function_destroyer (struct cmd_list_element
*self
, void *ignore
)
2139 xfree ((char *) self
->name
);
2143 /* Add a new internal function. NAME is the name of the function; DOC
2144 is a documentation string describing the function. HANDLER is
2145 called when the function is invoked. COOKIE is an arbitrary
2146 pointer which is passed to HANDLER and is intended for "user
2149 add_internal_function (const char *name
, const char *doc
,
2150 internal_function_fn handler
, void *cookie
)
2152 struct cmd_list_element
*cmd
;
2153 struct internal_function
*ifn
;
2154 struct internalvar
*var
= lookup_internalvar (name
);
2156 ifn
= create_internal_function (name
, handler
, cookie
);
2157 set_internalvar_function (var
, ifn
);
2159 cmd
= add_cmd (xstrdup (name
), no_class
, function_command
, (char *) doc
,
2161 cmd
->destroyer
= function_destroyer
;
2164 /* Update VALUE before discarding OBJFILE. COPIED_TYPES is used to
2165 prevent cycles / duplicates. */
2168 preserve_one_value (struct value
*value
, struct objfile
*objfile
,
2169 htab_t copied_types
)
2171 if (TYPE_OBJFILE (value
->type
) == objfile
)
2172 value
->type
= copy_type_recursive (objfile
, value
->type
, copied_types
);
2174 if (TYPE_OBJFILE (value
->enclosing_type
) == objfile
)
2175 value
->enclosing_type
= copy_type_recursive (objfile
,
2176 value
->enclosing_type
,
2180 /* Likewise for internal variable VAR. */
2183 preserve_one_internalvar (struct internalvar
*var
, struct objfile
*objfile
,
2184 htab_t copied_types
)
2188 case INTERNALVAR_INTEGER
:
2189 if (var
->u
.integer
.type
&& TYPE_OBJFILE (var
->u
.integer
.type
) == objfile
)
2191 = copy_type_recursive (objfile
, var
->u
.integer
.type
, copied_types
);
2194 case INTERNALVAR_VALUE
:
2195 preserve_one_value (var
->u
.value
, objfile
, copied_types
);
2200 /* Update the internal variables and value history when OBJFILE is
2201 discarded; we must copy the types out of the objfile. New global types
2202 will be created for every convenience variable which currently points to
2203 this objfile's types, and the convenience variables will be adjusted to
2204 use the new global types. */
2207 preserve_values (struct objfile
*objfile
)
2209 htab_t copied_types
;
2210 struct value_history_chunk
*cur
;
2211 struct internalvar
*var
;
2214 /* Create the hash table. We allocate on the objfile's obstack, since
2215 it is soon to be deleted. */
2216 copied_types
= create_copied_types_hash (objfile
);
2218 for (cur
= value_history_chain
; cur
; cur
= cur
->next
)
2219 for (i
= 0; i
< VALUE_HISTORY_CHUNK
; i
++)
2221 preserve_one_value (cur
->values
[i
], objfile
, copied_types
);
2223 for (var
= internalvars
; var
; var
= var
->next
)
2224 preserve_one_internalvar (var
, objfile
, copied_types
);
2226 preserve_python_values (objfile
, copied_types
);
2228 htab_delete (copied_types
);
2232 show_convenience (char *ignore
, int from_tty
)
2234 struct gdbarch
*gdbarch
= get_current_arch ();
2235 struct internalvar
*var
;
2237 struct value_print_options opts
;
2239 get_user_print_options (&opts
);
2240 for (var
= internalvars
; var
; var
= var
->next
)
2242 volatile struct gdb_exception ex
;
2248 printf_filtered (("$%s = "), var
->name
);
2250 TRY_CATCH (ex
, RETURN_MASK_ERROR
)
2254 val
= value_of_internalvar (gdbarch
, var
);
2255 value_print (val
, gdb_stdout
, &opts
);
2258 fprintf_filtered (gdb_stdout
, _("<error: %s>"), ex
.message
);
2259 printf_filtered (("\n"));
2263 /* This text does not mention convenience functions on purpose.
2264 The user can't create them except via Python, and if Python support
2265 is installed this message will never be printed ($_streq will
2267 printf_unfiltered (_("No debugger convenience variables now defined.\n"
2268 "Convenience variables have "
2269 "names starting with \"$\";\n"
2270 "use \"set\" as in \"set "
2271 "$foo = 5\" to define them.\n"));
2275 /* Extract a value as a C number (either long or double).
2276 Knows how to convert fixed values to double, or
2277 floating values to long.
2278 Does not deallocate the value. */
2281 value_as_long (struct value
*val
)
2283 /* This coerces arrays and functions, which is necessary (e.g.
2284 in disassemble_command). It also dereferences references, which
2285 I suspect is the most logical thing to do. */
2286 val
= coerce_array (val
);
2287 return unpack_long (value_type (val
), value_contents (val
));
2291 value_as_double (struct value
*val
)
2296 foo
= unpack_double (value_type (val
), value_contents (val
), &inv
);
2298 error (_("Invalid floating value found in program."));
2302 /* Extract a value as a C pointer. Does not deallocate the value.
2303 Note that val's type may not actually be a pointer; value_as_long
2304 handles all the cases. */
2306 value_as_address (struct value
*val
)
2308 struct gdbarch
*gdbarch
= get_type_arch (value_type (val
));
2310 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2311 whether we want this to be true eventually. */
2313 /* gdbarch_addr_bits_remove is wrong if we are being called for a
2314 non-address (e.g. argument to "signal", "info break", etc.), or
2315 for pointers to char, in which the low bits *are* significant. */
2316 return gdbarch_addr_bits_remove (gdbarch
, value_as_long (val
));
2319 /* There are several targets (IA-64, PowerPC, and others) which
2320 don't represent pointers to functions as simply the address of
2321 the function's entry point. For example, on the IA-64, a
2322 function pointer points to a two-word descriptor, generated by
2323 the linker, which contains the function's entry point, and the
2324 value the IA-64 "global pointer" register should have --- to
2325 support position-independent code. The linker generates
2326 descriptors only for those functions whose addresses are taken.
2328 On such targets, it's difficult for GDB to convert an arbitrary
2329 function address into a function pointer; it has to either find
2330 an existing descriptor for that function, or call malloc and
2331 build its own. On some targets, it is impossible for GDB to
2332 build a descriptor at all: the descriptor must contain a jump
2333 instruction; data memory cannot be executed; and code memory
2336 Upon entry to this function, if VAL is a value of type `function'
2337 (that is, TYPE_CODE (VALUE_TYPE (val)) == TYPE_CODE_FUNC), then
2338 value_address (val) is the address of the function. This is what
2339 you'll get if you evaluate an expression like `main'. The call
2340 to COERCE_ARRAY below actually does all the usual unary
2341 conversions, which includes converting values of type `function'
2342 to `pointer to function'. This is the challenging conversion
2343 discussed above. Then, `unpack_long' will convert that pointer
2344 back into an address.
2346 So, suppose the user types `disassemble foo' on an architecture
2347 with a strange function pointer representation, on which GDB
2348 cannot build its own descriptors, and suppose further that `foo'
2349 has no linker-built descriptor. The address->pointer conversion
2350 will signal an error and prevent the command from running, even
2351 though the next step would have been to convert the pointer
2352 directly back into the same address.
2354 The following shortcut avoids this whole mess. If VAL is a
2355 function, just return its address directly. */
2356 if (TYPE_CODE (value_type (val
)) == TYPE_CODE_FUNC
2357 || TYPE_CODE (value_type (val
)) == TYPE_CODE_METHOD
)
2358 return value_address (val
);
2360 val
= coerce_array (val
);
2362 /* Some architectures (e.g. Harvard), map instruction and data
2363 addresses onto a single large unified address space. For
2364 instance: An architecture may consider a large integer in the
2365 range 0x10000000 .. 0x1000ffff to already represent a data
2366 addresses (hence not need a pointer to address conversion) while
2367 a small integer would still need to be converted integer to
2368 pointer to address. Just assume such architectures handle all
2369 integer conversions in a single function. */
2373 I think INTEGER_TO_ADDRESS is a good idea as proposed --- but we
2374 must admonish GDB hackers to make sure its behavior matches the
2375 compiler's, whenever possible.
2377 In general, I think GDB should evaluate expressions the same way
2378 the compiler does. When the user copies an expression out of
2379 their source code and hands it to a `print' command, they should
2380 get the same value the compiler would have computed. Any
2381 deviation from this rule can cause major confusion and annoyance,
2382 and needs to be justified carefully. In other words, GDB doesn't
2383 really have the freedom to do these conversions in clever and
2386 AndrewC pointed out that users aren't complaining about how GDB
2387 casts integers to pointers; they are complaining that they can't
2388 take an address from a disassembly listing and give it to `x/i'.
2389 This is certainly important.
2391 Adding an architecture method like integer_to_address() certainly
2392 makes it possible for GDB to "get it right" in all circumstances
2393 --- the target has complete control over how things get done, so
2394 people can Do The Right Thing for their target without breaking
2395 anyone else. The standard doesn't specify how integers get
2396 converted to pointers; usually, the ABI doesn't either, but
2397 ABI-specific code is a more reasonable place to handle it. */
2399 if (TYPE_CODE (value_type (val
)) != TYPE_CODE_PTR
2400 && TYPE_CODE (value_type (val
)) != TYPE_CODE_REF
2401 && gdbarch_integer_to_address_p (gdbarch
))
2402 return gdbarch_integer_to_address (gdbarch
, value_type (val
),
2403 value_contents (val
));
2405 return unpack_long (value_type (val
), value_contents (val
));
2409 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2410 as a long, or as a double, assuming the raw data is described
2411 by type TYPE. Knows how to convert different sizes of values
2412 and can convert between fixed and floating point. We don't assume
2413 any alignment for the raw data. Return value is in host byte order.
2415 If you want functions and arrays to be coerced to pointers, and
2416 references to be dereferenced, call value_as_long() instead.
2418 C++: It is assumed that the front-end has taken care of
2419 all matters concerning pointers to members. A pointer
2420 to member which reaches here is considered to be equivalent
2421 to an INT (or some size). After all, it is only an offset. */
2424 unpack_long (struct type
*type
, const gdb_byte
*valaddr
)
2426 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2427 enum type_code code
= TYPE_CODE (type
);
2428 int len
= TYPE_LENGTH (type
);
2429 int nosign
= TYPE_UNSIGNED (type
);
2433 case TYPE_CODE_TYPEDEF
:
2434 return unpack_long (check_typedef (type
), valaddr
);
2435 case TYPE_CODE_ENUM
:
2436 case TYPE_CODE_FLAGS
:
2437 case TYPE_CODE_BOOL
:
2439 case TYPE_CODE_CHAR
:
2440 case TYPE_CODE_RANGE
:
2441 case TYPE_CODE_MEMBERPTR
:
2443 return extract_unsigned_integer (valaddr
, len
, byte_order
);
2445 return extract_signed_integer (valaddr
, len
, byte_order
);
2448 return extract_typed_floating (valaddr
, type
);
2450 case TYPE_CODE_DECFLOAT
:
2451 /* libdecnumber has a function to convert from decimal to integer, but
2452 it doesn't work when the decimal number has a fractional part. */
2453 return decimal_to_doublest (valaddr
, len
, byte_order
);
2457 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2458 whether we want this to be true eventually. */
2459 return extract_typed_address (valaddr
, type
);
2462 error (_("Value can't be converted to integer."));
2464 return 0; /* Placate lint. */
2467 /* Return a double value from the specified type and address.
2468 INVP points to an int which is set to 0 for valid value,
2469 1 for invalid value (bad float format). In either case,
2470 the returned double is OK to use. Argument is in target
2471 format, result is in host format. */
2474 unpack_double (struct type
*type
, const gdb_byte
*valaddr
, int *invp
)
2476 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
2477 enum type_code code
;
2481 *invp
= 0; /* Assume valid. */
2482 CHECK_TYPEDEF (type
);
2483 code
= TYPE_CODE (type
);
2484 len
= TYPE_LENGTH (type
);
2485 nosign
= TYPE_UNSIGNED (type
);
2486 if (code
== TYPE_CODE_FLT
)
2488 /* NOTE: cagney/2002-02-19: There was a test here to see if the
2489 floating-point value was valid (using the macro
2490 INVALID_FLOAT). That test/macro have been removed.
2492 It turns out that only the VAX defined this macro and then
2493 only in a non-portable way. Fixing the portability problem
2494 wouldn't help since the VAX floating-point code is also badly
2495 bit-rotten. The target needs to add definitions for the
2496 methods gdbarch_float_format and gdbarch_double_format - these
2497 exactly describe the target floating-point format. The
2498 problem here is that the corresponding floatformat_vax_f and
2499 floatformat_vax_d values these methods should be set to are
2500 also not defined either. Oops!
2502 Hopefully someone will add both the missing floatformat
2503 definitions and the new cases for floatformat_is_valid (). */
2505 if (!floatformat_is_valid (floatformat_from_type (type
), valaddr
))
2511 return extract_typed_floating (valaddr
, type
);
2513 else if (code
== TYPE_CODE_DECFLOAT
)
2514 return decimal_to_doublest (valaddr
, len
, byte_order
);
2517 /* Unsigned -- be sure we compensate for signed LONGEST. */
2518 return (ULONGEST
) unpack_long (type
, valaddr
);
2522 /* Signed -- we are OK with unpack_long. */
2523 return unpack_long (type
, valaddr
);
2527 /* Unpack raw data (copied from debugee, target byte order) at VALADDR
2528 as a CORE_ADDR, assuming the raw data is described by type TYPE.
2529 We don't assume any alignment for the raw data. Return value is in
2532 If you want functions and arrays to be coerced to pointers, and
2533 references to be dereferenced, call value_as_address() instead.
2535 C++: It is assumed that the front-end has taken care of
2536 all matters concerning pointers to members. A pointer
2537 to member which reaches here is considered to be equivalent
2538 to an INT (or some size). After all, it is only an offset. */
2541 unpack_pointer (struct type
*type
, const gdb_byte
*valaddr
)
2543 /* Assume a CORE_ADDR can fit in a LONGEST (for now). Not sure
2544 whether we want this to be true eventually. */
2545 return unpack_long (type
, valaddr
);
2549 /* Get the value of the FIELDNO'th field (which must be static) of
2550 TYPE. Return NULL if the field doesn't exist or has been
2554 value_static_field (struct type
*type
, int fieldno
)
2556 struct value
*retval
;
2558 switch (TYPE_FIELD_LOC_KIND (type
, fieldno
))
2560 case FIELD_LOC_KIND_PHYSADDR
:
2561 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2562 TYPE_FIELD_STATIC_PHYSADDR (type
, fieldno
));
2564 case FIELD_LOC_KIND_PHYSNAME
:
2566 const char *phys_name
= TYPE_FIELD_STATIC_PHYSNAME (type
, fieldno
);
2567 /* TYPE_FIELD_NAME (type, fieldno); */
2568 struct symbol
*sym
= lookup_symbol (phys_name
, 0, VAR_DOMAIN
, 0);
2572 /* With some compilers, e.g. HP aCC, static data members are
2573 reported as non-debuggable symbols. */
2574 struct minimal_symbol
*msym
= lookup_minimal_symbol (phys_name
,
2581 retval
= value_at_lazy (TYPE_FIELD_TYPE (type
, fieldno
),
2582 SYMBOL_VALUE_ADDRESS (msym
));
2586 retval
= value_of_variable (sym
, NULL
);
2590 gdb_assert_not_reached ("unexpected field location kind");
2596 /* Change the enclosing type of a value object VAL to NEW_ENCL_TYPE.
2597 You have to be careful here, since the size of the data area for the value
2598 is set by the length of the enclosing type. So if NEW_ENCL_TYPE is bigger
2599 than the old enclosing type, you have to allocate more space for the
2603 set_value_enclosing_type (struct value
*val
, struct type
*new_encl_type
)
2605 if (TYPE_LENGTH (new_encl_type
) > TYPE_LENGTH (value_enclosing_type (val
)))
2607 (gdb_byte
*) xrealloc (val
->contents
, TYPE_LENGTH (new_encl_type
));
2609 val
->enclosing_type
= new_encl_type
;
2612 /* Given a value ARG1 (offset by OFFSET bytes)
2613 of a struct or union type ARG_TYPE,
2614 extract and return the value of one of its (non-static) fields.
2615 FIELDNO says which field. */
2618 value_primitive_field (struct value
*arg1
, int offset
,
2619 int fieldno
, struct type
*arg_type
)
2624 CHECK_TYPEDEF (arg_type
);
2625 type
= TYPE_FIELD_TYPE (arg_type
, fieldno
);
2627 /* Call check_typedef on our type to make sure that, if TYPE
2628 is a TYPE_CODE_TYPEDEF, its length is set to the length
2629 of the target type instead of zero. However, we do not
2630 replace the typedef type by the target type, because we want
2631 to keep the typedef in order to be able to print the type
2632 description correctly. */
2633 check_typedef (type
);
2635 if (TYPE_FIELD_BITSIZE (arg_type
, fieldno
))
2637 /* Handle packed fields.
2639 Create a new value for the bitfield, with bitpos and bitsize
2640 set. If possible, arrange offset and bitpos so that we can
2641 do a single aligned read of the size of the containing type.
2642 Otherwise, adjust offset to the byte containing the first
2643 bit. Assume that the address, offset, and embedded offset
2644 are sufficiently aligned. */
2646 int bitpos
= TYPE_FIELD_BITPOS (arg_type
, fieldno
);
2647 int container_bitsize
= TYPE_LENGTH (type
) * 8;
2649 if (arg1
->optimized_out
)
2650 v
= allocate_optimized_out_value (type
);
2653 v
= allocate_value_lazy (type
);
2654 v
->bitsize
= TYPE_FIELD_BITSIZE (arg_type
, fieldno
);
2655 if ((bitpos
% container_bitsize
) + v
->bitsize
<= container_bitsize
2656 && TYPE_LENGTH (type
) <= (int) sizeof (LONGEST
))
2657 v
->bitpos
= bitpos
% container_bitsize
;
2659 v
->bitpos
= bitpos
% 8;
2660 v
->offset
= (value_embedded_offset (arg1
)
2662 + (bitpos
- v
->bitpos
) / 8);
2663 set_value_parent (v
, arg1
);
2664 if (!value_lazy (arg1
))
2665 value_fetch_lazy (v
);
2668 else if (fieldno
< TYPE_N_BASECLASSES (arg_type
))
2670 /* This field is actually a base subobject, so preserve the
2671 entire object's contents for later references to virtual
2675 /* Lazy register values with offsets are not supported. */
2676 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2677 value_fetch_lazy (arg1
);
2679 /* The optimized_out flag is only set correctly once a lazy value is
2680 loaded, having just loaded some lazy values we should check the
2681 optimized out case now. */
2682 if (arg1
->optimized_out
)
2683 v
= allocate_optimized_out_value (type
);
2686 /* We special case virtual inheritance here because this
2687 requires access to the contents, which we would rather avoid
2688 for references to ordinary fields of unavailable values. */
2689 if (BASETYPE_VIA_VIRTUAL (arg_type
, fieldno
))
2690 boffset
= baseclass_offset (arg_type
, fieldno
,
2691 value_contents (arg1
),
2692 value_embedded_offset (arg1
),
2693 value_address (arg1
),
2696 boffset
= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2698 if (value_lazy (arg1
))
2699 v
= allocate_value_lazy (value_enclosing_type (arg1
));
2702 v
= allocate_value (value_enclosing_type (arg1
));
2703 value_contents_copy_raw (v
, 0, arg1
, 0,
2704 TYPE_LENGTH (value_enclosing_type (arg1
)));
2707 v
->offset
= value_offset (arg1
);
2708 v
->embedded_offset
= offset
+ value_embedded_offset (arg1
) + boffset
;
2713 /* Plain old data member */
2714 offset
+= TYPE_FIELD_BITPOS (arg_type
, fieldno
) / 8;
2716 /* Lazy register values with offsets are not supported. */
2717 if (VALUE_LVAL (arg1
) == lval_register
&& value_lazy (arg1
))
2718 value_fetch_lazy (arg1
);
2720 /* The optimized_out flag is only set correctly once a lazy value is
2721 loaded, having just loaded some lazy values we should check for
2722 the optimized out case now. */
2723 if (arg1
->optimized_out
)
2724 v
= allocate_optimized_out_value (type
);
2725 else if (value_lazy (arg1
))
2726 v
= allocate_value_lazy (type
);
2729 v
= allocate_value (type
);
2730 value_contents_copy_raw (v
, value_embedded_offset (v
),
2731 arg1
, value_embedded_offset (arg1
) + offset
,
2732 TYPE_LENGTH (type
));
2734 v
->offset
= (value_offset (arg1
) + offset
2735 + value_embedded_offset (arg1
));
2737 set_value_component_location (v
, arg1
);
2738 VALUE_REGNUM (v
) = VALUE_REGNUM (arg1
);
2739 VALUE_FRAME_ID (v
) = VALUE_FRAME_ID (arg1
);
2743 /* Given a value ARG1 of a struct or union type,
2744 extract and return the value of one of its (non-static) fields.
2745 FIELDNO says which field. */
2748 value_field (struct value
*arg1
, int fieldno
)
2750 return value_primitive_field (arg1
, 0, fieldno
, value_type (arg1
));
2753 /* Return a non-virtual function as a value.
2754 F is the list of member functions which contains the desired method.
2755 J is an index into F which provides the desired method.
2757 We only use the symbol for its address, so be happy with either a
2758 full symbol or a minimal symbol. */
2761 value_fn_field (struct value
**arg1p
, struct fn_field
*f
,
2762 int j
, struct type
*type
,
2766 struct type
*ftype
= TYPE_FN_FIELD_TYPE (f
, j
);
2767 const char *physname
= TYPE_FN_FIELD_PHYSNAME (f
, j
);
2769 struct minimal_symbol
*msym
;
2771 sym
= lookup_symbol (physname
, 0, VAR_DOMAIN
, 0);
2778 gdb_assert (sym
== NULL
);
2779 msym
= lookup_minimal_symbol (physname
, NULL
, NULL
);
2784 v
= allocate_value (ftype
);
2787 set_value_address (v
, BLOCK_START (SYMBOL_BLOCK_VALUE (sym
)));
2791 /* The minimal symbol might point to a function descriptor;
2792 resolve it to the actual code address instead. */
2793 struct objfile
*objfile
= msymbol_objfile (msym
);
2794 struct gdbarch
*gdbarch
= get_objfile_arch (objfile
);
2796 set_value_address (v
,
2797 gdbarch_convert_from_func_ptr_addr
2798 (gdbarch
, SYMBOL_VALUE_ADDRESS (msym
), ¤t_target
));
2803 if (type
!= value_type (*arg1p
))
2804 *arg1p
= value_ind (value_cast (lookup_pointer_type (type
),
2805 value_addr (*arg1p
)));
2807 /* Move the `this' pointer according to the offset.
2808 VALUE_OFFSET (*arg1p) += offset; */
2816 /* Helper function for both unpack_value_bits_as_long and
2817 unpack_bits_as_long. See those functions for more details on the
2818 interface; the only difference is that this function accepts either
2819 a NULL or a non-NULL ORIGINAL_VALUE. */
2822 unpack_value_bits_as_long_1 (struct type
*field_type
, const gdb_byte
*valaddr
,
2823 int embedded_offset
, int bitpos
, int bitsize
,
2824 const struct value
*original_value
,
2827 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (field_type
));
2834 /* Read the minimum number of bytes required; there may not be
2835 enough bytes to read an entire ULONGEST. */
2836 CHECK_TYPEDEF (field_type
);
2838 bytes_read
= ((bitpos
% 8) + bitsize
+ 7) / 8;
2840 bytes_read
= TYPE_LENGTH (field_type
);
2842 read_offset
= bitpos
/ 8;
2844 if (original_value
!= NULL
2845 && !value_bytes_available (original_value
, embedded_offset
+ read_offset
,
2849 val
= extract_unsigned_integer (valaddr
+ embedded_offset
+ read_offset
,
2850 bytes_read
, byte_order
);
2852 /* Extract bits. See comment above. */
2854 if (gdbarch_bits_big_endian (get_type_arch (field_type
)))
2855 lsbcount
= (bytes_read
* 8 - bitpos
% 8 - bitsize
);
2857 lsbcount
= (bitpos
% 8);
2860 /* If the field does not entirely fill a LONGEST, then zero the sign bits.
2861 If the field is signed, and is negative, then sign extend. */
2863 if ((bitsize
> 0) && (bitsize
< 8 * (int) sizeof (val
)))
2865 valmask
= (((ULONGEST
) 1) << bitsize
) - 1;
2867 if (!TYPE_UNSIGNED (field_type
))
2869 if (val
& (valmask
^ (valmask
>> 1)))
2880 /* Unpack a bitfield of the specified FIELD_TYPE, from the object at
2881 VALADDR + EMBEDDED_OFFSET, and store the result in *RESULT.
2882 VALADDR points to the contents of ORIGINAL_VALUE, which must not be
2883 NULL. The bitfield starts at BITPOS bits and contains BITSIZE
2886 Returns false if the value contents are unavailable, otherwise
2887 returns true, indicating a valid value has been stored in *RESULT.
2889 Extracting bits depends on endianness of the machine. Compute the
2890 number of least significant bits to discard. For big endian machines,
2891 we compute the total number of bits in the anonymous object, subtract
2892 off the bit count from the MSB of the object to the MSB of the
2893 bitfield, then the size of the bitfield, which leaves the LSB discard
2894 count. For little endian machines, the discard count is simply the
2895 number of bits from the LSB of the anonymous object to the LSB of the
2898 If the field is signed, we also do sign extension. */
2901 unpack_value_bits_as_long (struct type
*field_type
, const gdb_byte
*valaddr
,
2902 int embedded_offset
, int bitpos
, int bitsize
,
2903 const struct value
*original_value
,
2906 gdb_assert (original_value
!= NULL
);
2908 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2909 bitpos
, bitsize
, original_value
, result
);
2913 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2914 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2915 ORIGINAL_VALUE. See unpack_value_bits_as_long for more
2919 unpack_value_field_as_long_1 (struct type
*type
, const gdb_byte
*valaddr
,
2920 int embedded_offset
, int fieldno
,
2921 const struct value
*val
, LONGEST
*result
)
2923 int bitpos
= TYPE_FIELD_BITPOS (type
, fieldno
);
2924 int bitsize
= TYPE_FIELD_BITSIZE (type
, fieldno
);
2925 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2927 return unpack_value_bits_as_long_1 (field_type
, valaddr
, embedded_offset
,
2928 bitpos
, bitsize
, val
,
2932 /* Unpack a field FIELDNO of the specified TYPE, from the object at
2933 VALADDR + EMBEDDED_OFFSET. VALADDR points to the contents of
2934 ORIGINAL_VALUE, which must not be NULL. See
2935 unpack_value_bits_as_long for more details. */
2938 unpack_value_field_as_long (struct type
*type
, const gdb_byte
*valaddr
,
2939 int embedded_offset
, int fieldno
,
2940 const struct value
*val
, LONGEST
*result
)
2942 gdb_assert (val
!= NULL
);
2944 return unpack_value_field_as_long_1 (type
, valaddr
, embedded_offset
,
2945 fieldno
, val
, result
);
2948 /* Unpack a field FIELDNO of the specified TYPE, from the anonymous
2949 object at VALADDR. See unpack_value_bits_as_long for more details.
2950 This function differs from unpack_value_field_as_long in that it
2951 operates without a struct value object. */
2954 unpack_field_as_long (struct type
*type
, const gdb_byte
*valaddr
, int fieldno
)
2958 unpack_value_field_as_long_1 (type
, valaddr
, 0, fieldno
, NULL
, &result
);
2962 /* Return a new value with type TYPE, which is FIELDNO field of the
2963 object at VALADDR + EMBEDDEDOFFSET. VALADDR points to the contents
2964 of VAL. If the VAL's contents required to extract the bitfield
2965 from are unavailable, the new value is correspondingly marked as
2969 value_field_bitfield (struct type
*type
, int fieldno
,
2970 const gdb_byte
*valaddr
,
2971 int embedded_offset
, const struct value
*val
)
2975 if (!unpack_value_field_as_long (type
, valaddr
, embedded_offset
, fieldno
,
2978 struct type
*field_type
= TYPE_FIELD_TYPE (type
, fieldno
);
2979 struct value
*retval
= allocate_value (field_type
);
2980 mark_value_bytes_unavailable (retval
, 0, TYPE_LENGTH (field_type
));
2985 return value_from_longest (TYPE_FIELD_TYPE (type
, fieldno
), l
);
2989 /* Modify the value of a bitfield. ADDR points to a block of memory in
2990 target byte order; the bitfield starts in the byte pointed to. FIELDVAL
2991 is the desired value of the field, in host byte order. BITPOS and BITSIZE
2992 indicate which bits (in target bit order) comprise the bitfield.
2993 Requires 0 < BITSIZE <= lbits, 0 <= BITPOS % 8 + BITSIZE <= lbits, and
2994 0 <= BITPOS, where lbits is the size of a LONGEST in bits. */
2997 modify_field (struct type
*type
, gdb_byte
*addr
,
2998 LONGEST fieldval
, int bitpos
, int bitsize
)
3000 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3002 ULONGEST mask
= (ULONGEST
) -1 >> (8 * sizeof (ULONGEST
) - bitsize
);
3005 /* Normalize BITPOS. */
3009 /* If a negative fieldval fits in the field in question, chop
3010 off the sign extension bits. */
3011 if ((~fieldval
& ~(mask
>> 1)) == 0)
3014 /* Warn if value is too big to fit in the field in question. */
3015 if (0 != (fieldval
& ~mask
))
3017 /* FIXME: would like to include fieldval in the message, but
3018 we don't have a sprintf_longest. */
3019 warning (_("Value does not fit in %d bits."), bitsize
);
3021 /* Truncate it, otherwise adjoining fields may be corrupted. */
3025 /* Ensure no bytes outside of the modified ones get accessed as it may cause
3026 false valgrind reports. */
3028 bytesize
= (bitpos
+ bitsize
+ 7) / 8;
3029 oword
= extract_unsigned_integer (addr
, bytesize
, byte_order
);
3031 /* Shifting for bit field depends on endianness of the target machine. */
3032 if (gdbarch_bits_big_endian (get_type_arch (type
)))
3033 bitpos
= bytesize
* 8 - bitpos
- bitsize
;
3035 oword
&= ~(mask
<< bitpos
);
3036 oword
|= fieldval
<< bitpos
;
3038 store_unsigned_integer (addr
, bytesize
, byte_order
, oword
);
3041 /* Pack NUM into BUF using a target format of TYPE. */
3044 pack_long (gdb_byte
*buf
, struct type
*type
, LONGEST num
)
3046 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3049 type
= check_typedef (type
);
3050 len
= TYPE_LENGTH (type
);
3052 switch (TYPE_CODE (type
))
3055 case TYPE_CODE_CHAR
:
3056 case TYPE_CODE_ENUM
:
3057 case TYPE_CODE_FLAGS
:
3058 case TYPE_CODE_BOOL
:
3059 case TYPE_CODE_RANGE
:
3060 case TYPE_CODE_MEMBERPTR
:
3061 store_signed_integer (buf
, len
, byte_order
, num
);
3066 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3070 error (_("Unexpected type (%d) encountered for integer constant."),
3076 /* Pack NUM into BUF using a target format of TYPE. */
3079 pack_unsigned_long (gdb_byte
*buf
, struct type
*type
, ULONGEST num
)
3082 enum bfd_endian byte_order
;
3084 type
= check_typedef (type
);
3085 len
= TYPE_LENGTH (type
);
3086 byte_order
= gdbarch_byte_order (get_type_arch (type
));
3088 switch (TYPE_CODE (type
))
3091 case TYPE_CODE_CHAR
:
3092 case TYPE_CODE_ENUM
:
3093 case TYPE_CODE_FLAGS
:
3094 case TYPE_CODE_BOOL
:
3095 case TYPE_CODE_RANGE
:
3096 case TYPE_CODE_MEMBERPTR
:
3097 store_unsigned_integer (buf
, len
, byte_order
, num
);
3102 store_typed_address (buf
, type
, (CORE_ADDR
) num
);
3106 error (_("Unexpected type (%d) encountered "
3107 "for unsigned integer constant."),
3113 /* Convert C numbers into newly allocated values. */
3116 value_from_longest (struct type
*type
, LONGEST num
)
3118 struct value
*val
= allocate_value (type
);
3120 pack_long (value_contents_raw (val
), type
, num
);
3125 /* Convert C unsigned numbers into newly allocated values. */
3128 value_from_ulongest (struct type
*type
, ULONGEST num
)
3130 struct value
*val
= allocate_value (type
);
3132 pack_unsigned_long (value_contents_raw (val
), type
, num
);
3138 /* Create a value representing a pointer of type TYPE to the address
3141 value_from_pointer (struct type
*type
, CORE_ADDR addr
)
3143 struct value
*val
= allocate_value (type
);
3145 store_typed_address (value_contents_raw (val
), check_typedef (type
), addr
);
3150 /* Create a value of type TYPE whose contents come from VALADDR, if it
3151 is non-null, and whose memory address (in the inferior) is
3155 value_from_contents_and_address (struct type
*type
,
3156 const gdb_byte
*valaddr
,
3161 if (valaddr
== NULL
)
3162 v
= allocate_value_lazy (type
);
3165 v
= allocate_value (type
);
3166 memcpy (value_contents_raw (v
), valaddr
, TYPE_LENGTH (type
));
3168 set_value_address (v
, address
);
3169 VALUE_LVAL (v
) = lval_memory
;
3173 /* Create a value of type TYPE holding the contents CONTENTS.
3174 The new value is `not_lval'. */
3177 value_from_contents (struct type
*type
, const gdb_byte
*contents
)
3179 struct value
*result
;
3181 result
= allocate_value (type
);
3182 memcpy (value_contents_raw (result
), contents
, TYPE_LENGTH (type
));
3187 value_from_double (struct type
*type
, DOUBLEST num
)
3189 struct value
*val
= allocate_value (type
);
3190 struct type
*base_type
= check_typedef (type
);
3191 enum type_code code
= TYPE_CODE (base_type
);
3193 if (code
== TYPE_CODE_FLT
)
3195 store_typed_floating (value_contents_raw (val
), base_type
, num
);
3198 error (_("Unexpected type encountered for floating constant."));
3204 value_from_decfloat (struct type
*type
, const gdb_byte
*dec
)
3206 struct value
*val
= allocate_value (type
);
3208 memcpy (value_contents_raw (val
), dec
, TYPE_LENGTH (type
));
3212 /* Extract a value from the history file. Input will be of the form
3213 $digits or $$digits. See block comment above 'write_dollar_variable'
3217 value_from_history_ref (char *h
, char **endp
)
3229 /* Find length of numeral string. */
3230 for (; isdigit (h
[len
]); len
++)
3233 /* Make sure numeral string is not part of an identifier. */
3234 if (h
[len
] == '_' || isalpha (h
[len
]))
3237 /* Now collect the index value. */
3242 /* For some bizarre reason, "$$" is equivalent to "$$1",
3243 rather than to "$$0" as it ought to be! */
3248 index
= -strtol (&h
[2], endp
, 10);
3254 /* "$" is equivalent to "$0". */
3259 index
= strtol (&h
[1], endp
, 10);
3262 return access_value_history (index
);
3266 coerce_ref_if_computed (const struct value
*arg
)
3268 const struct lval_funcs
*funcs
;
3270 if (TYPE_CODE (check_typedef (value_type (arg
))) != TYPE_CODE_REF
)
3273 if (value_lval_const (arg
) != lval_computed
)
3276 funcs
= value_computed_funcs (arg
);
3277 if (funcs
->coerce_ref
== NULL
)
3280 return funcs
->coerce_ref (arg
);
3283 /* Look at value.h for description. */
3286 readjust_indirect_value_type (struct value
*value
, struct type
*enc_type
,
3287 struct type
*original_type
,
3288 struct value
*original_value
)
3290 /* Re-adjust type. */
3291 deprecated_set_value_type (value
, TYPE_TARGET_TYPE (original_type
));
3293 /* Add embedding info. */
3294 set_value_enclosing_type (value
, enc_type
);
3295 set_value_embedded_offset (value
, value_pointed_to_offset (original_value
));
3297 /* We may be pointing to an object of some derived type. */
3298 return value_full_object (value
, NULL
, 0, 0, 0);
3302 coerce_ref (struct value
*arg
)
3304 struct type
*value_type_arg_tmp
= check_typedef (value_type (arg
));
3305 struct value
*retval
;
3306 struct type
*enc_type
;
3308 retval
= coerce_ref_if_computed (arg
);
3312 if (TYPE_CODE (value_type_arg_tmp
) != TYPE_CODE_REF
)
3315 enc_type
= check_typedef (value_enclosing_type (arg
));
3316 enc_type
= TYPE_TARGET_TYPE (enc_type
);
3318 retval
= value_at_lazy (enc_type
,
3319 unpack_pointer (value_type (arg
),
3320 value_contents (arg
)));
3321 return readjust_indirect_value_type (retval
, enc_type
,
3322 value_type_arg_tmp
, arg
);
3326 coerce_array (struct value
*arg
)
3330 arg
= coerce_ref (arg
);
3331 type
= check_typedef (value_type (arg
));
3333 switch (TYPE_CODE (type
))
3335 case TYPE_CODE_ARRAY
:
3336 if (!TYPE_VECTOR (type
) && current_language
->c_style_arrays
)
3337 arg
= value_coerce_array (arg
);
3339 case TYPE_CODE_FUNC
:
3340 arg
= value_coerce_function (arg
);
3347 /* Return the return value convention that will be used for the
3350 enum return_value_convention
3351 struct_return_convention (struct gdbarch
*gdbarch
,
3352 struct value
*function
, struct type
*value_type
)
3354 enum type_code code
= TYPE_CODE (value_type
);
3356 if (code
== TYPE_CODE_ERROR
)
3357 error (_("Function return type unknown."));
3359 /* Probe the architecture for the return-value convention. */
3360 return gdbarch_return_value (gdbarch
, function
, value_type
,
3364 /* Return true if the function returning the specified type is using
3365 the convention of returning structures in memory (passing in the
3366 address as a hidden first parameter). */
3369 using_struct_return (struct gdbarch
*gdbarch
,
3370 struct value
*function
, struct type
*value_type
)
3372 if (TYPE_CODE (value_type
) == TYPE_CODE_VOID
)
3373 /* A void return value is never in memory. See also corresponding
3374 code in "print_return_value". */
3377 return (struct_return_convention (gdbarch
, function
, value_type
)
3378 != RETURN_VALUE_REGISTER_CONVENTION
);
3381 /* Set the initialized field in a value struct. */
3384 set_value_initialized (struct value
*val
, int status
)
3386 val
->initialized
= status
;
3389 /* Return the initialized field in a value struct. */
3392 value_initialized (struct value
*val
)
3394 return val
->initialized
;
3397 /* Called only from the value_contents and value_contents_all()
3398 macros, if the current data for a variable needs to be loaded into
3399 value_contents(VAL). Fetches the data from the user's process, and
3400 clears the lazy flag to indicate that the data in the buffer is
3403 If the value is zero-length, we avoid calling read_memory, which
3404 would abort. We mark the value as fetched anyway -- all 0 bytes of
3407 This function returns a value because it is used in the
3408 value_contents macro as part of an expression, where a void would
3409 not work. The value is ignored. */
3412 value_fetch_lazy (struct value
*val
)
3414 gdb_assert (value_lazy (val
));
3415 allocate_value_contents (val
);
3416 if (value_bitsize (val
))
3418 /* To read a lazy bitfield, read the entire enclosing value. This
3419 prevents reading the same block of (possibly volatile) memory once
3420 per bitfield. It would be even better to read only the containing
3421 word, but we have no way to record that just specific bits of a
3422 value have been fetched. */
3423 struct type
*type
= check_typedef (value_type (val
));
3424 enum bfd_endian byte_order
= gdbarch_byte_order (get_type_arch (type
));
3425 struct value
*parent
= value_parent (val
);
3426 LONGEST offset
= value_offset (val
);
3429 if (!value_bits_valid (val
,
3430 TARGET_CHAR_BIT
* offset
+ value_bitpos (val
),
3431 value_bitsize (val
)))
3432 error (_("value has been optimized out"));
3434 if (!unpack_value_bits_as_long (value_type (val
),
3435 value_contents_for_printing (parent
),
3438 value_bitsize (val
), parent
, &num
))
3439 mark_value_bytes_unavailable (val
,
3440 value_embedded_offset (val
),
3441 TYPE_LENGTH (type
));
3443 store_signed_integer (value_contents_raw (val
), TYPE_LENGTH (type
),
3446 else if (VALUE_LVAL (val
) == lval_memory
)
3448 CORE_ADDR addr
= value_address (val
);
3449 struct type
*type
= check_typedef (value_enclosing_type (val
));
3451 if (TYPE_LENGTH (type
))
3452 read_value_memory (val
, 0, value_stack (val
),
3453 addr
, value_contents_all_raw (val
),
3454 TYPE_LENGTH (type
));
3456 else if (VALUE_LVAL (val
) == lval_register
)
3458 struct frame_info
*frame
;
3460 struct type
*type
= check_typedef (value_type (val
));
3461 struct value
*new_val
= val
, *mark
= value_mark ();
3463 /* Offsets are not supported here; lazy register values must
3464 refer to the entire register. */
3465 gdb_assert (value_offset (val
) == 0);
3467 while (VALUE_LVAL (new_val
) == lval_register
&& value_lazy (new_val
))
3469 frame
= frame_find_by_id (VALUE_FRAME_ID (new_val
));
3470 regnum
= VALUE_REGNUM (new_val
);
3472 gdb_assert (frame
!= NULL
);
3474 /* Convertible register routines are used for multi-register
3475 values and for interpretation in different types
3476 (e.g. float or int from a double register). Lazy
3477 register values should have the register's natural type,
3478 so they do not apply. */
3479 gdb_assert (!gdbarch_convert_register_p (get_frame_arch (frame
),
3482 new_val
= get_frame_register_value (frame
, regnum
);
3485 /* If it's still lazy (for instance, a saved register on the
3486 stack), fetch it. */
3487 if (value_lazy (new_val
))
3488 value_fetch_lazy (new_val
);
3490 /* If the register was not saved, mark it optimized out. */
3491 if (value_optimized_out (new_val
))
3492 set_value_optimized_out (val
, 1);
3495 set_value_lazy (val
, 0);
3496 value_contents_copy (val
, value_embedded_offset (val
),
3497 new_val
, value_embedded_offset (new_val
),
3498 TYPE_LENGTH (type
));
3503 struct gdbarch
*gdbarch
;
3504 frame
= frame_find_by_id (VALUE_FRAME_ID (val
));
3505 regnum
= VALUE_REGNUM (val
);
3506 gdbarch
= get_frame_arch (frame
);
3508 fprintf_unfiltered (gdb_stdlog
,
3509 "{ value_fetch_lazy "
3510 "(frame=%d,regnum=%d(%s),...) ",
3511 frame_relative_level (frame
), regnum
,
3512 user_reg_map_regnum_to_name (gdbarch
, regnum
));
3514 fprintf_unfiltered (gdb_stdlog
, "->");
3515 if (value_optimized_out (new_val
))
3516 fprintf_unfiltered (gdb_stdlog
, " optimized out");
3520 const gdb_byte
*buf
= value_contents (new_val
);
3522 if (VALUE_LVAL (new_val
) == lval_register
)
3523 fprintf_unfiltered (gdb_stdlog
, " register=%d",
3524 VALUE_REGNUM (new_val
));
3525 else if (VALUE_LVAL (new_val
) == lval_memory
)
3526 fprintf_unfiltered (gdb_stdlog
, " address=%s",
3528 value_address (new_val
)));
3530 fprintf_unfiltered (gdb_stdlog
, " computed");
3532 fprintf_unfiltered (gdb_stdlog
, " bytes=");
3533 fprintf_unfiltered (gdb_stdlog
, "[");
3534 for (i
= 0; i
< register_size (gdbarch
, regnum
); i
++)
3535 fprintf_unfiltered (gdb_stdlog
, "%02x", buf
[i
]);
3536 fprintf_unfiltered (gdb_stdlog
, "]");
3539 fprintf_unfiltered (gdb_stdlog
, " }\n");
3542 /* Dispose of the intermediate values. This prevents
3543 watchpoints from trying to watch the saved frame pointer. */
3544 value_free_to_mark (mark
);
3546 else if (VALUE_LVAL (val
) == lval_computed
3547 && value_computed_funcs (val
)->read
!= NULL
)
3548 value_computed_funcs (val
)->read (val
);
3549 /* Don't call value_optimized_out on val, doing so would result in a
3550 recursive call back to value_fetch_lazy, instead check the
3551 optimized_out flag directly. */
3552 else if (val
->optimized_out
)
3553 /* Keep it optimized out. */;
3555 internal_error (__FILE__
, __LINE__
, _("Unexpected lazy value type."));
3557 set_value_lazy (val
, 0);
3562 _initialize_values (void)
3564 add_cmd ("convenience", no_class
, show_convenience
, _("\
3565 Debugger convenience (\"$foo\") variables and functions.\n\
3566 Convenience variables are created when you assign them values;\n\
3567 thus, \"set $foo=1\" gives \"$foo\" the value 1. Values may be any type.\n\
3569 A few convenience variables are given values automatically:\n\
3570 \"$_\"holds the last address examined with \"x\" or \"info lines\",\n\
3571 \"$__\" holds the contents of the last address examined with \"x\"."
3574 Convenience functions are defined via the Python API."
3577 add_alias_cmd ("conv", "convenience", no_class
, 1, &showlist
);
3579 add_cmd ("values", no_set_class
, show_values
, _("\
3580 Elements of value history around item number IDX (or last ten)."),
3583 add_com ("init-if-undefined", class_vars
, init_if_undefined_command
, _("\
3584 Initialize a convenience variable if necessary.\n\
3585 init-if-undefined VARIABLE = EXPRESSION\n\
3586 Set an internal VARIABLE to the result of the EXPRESSION if it does not\n\
3587 exist or does not contain a value. The EXPRESSION is not evaluated if the\n\
3588 VARIABLE is already initialized."));
3590 add_prefix_cmd ("function", no_class
, function_command
, _("\
3591 Placeholder command for showing help on convenience functions."),
3592 &functionlist
, "function ", 0, &cmdlist
);